Localized cartilage defect therapy

ABSTRACT

Methods of repairing cartilage defects are provided. The cartilage defect is identified and shaped to prepare the cartilage defect for a localized therapy. The cartilage defect is isolated with an isolation device. The localized therapy is then delivered to the cartilage defect through the isolation device.

FIELD

The present disclosure relates to apparatuses and methods for cartilagedefect therapy.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Articular cartilage enables bones to move smoothly relative to oneanother. Damage to the articular cartilage and the underlying bone canbe caused by injury, such as tearing, by excessive wear, or by alifetime of use. Damage to articular cartilage, particularly of theload-bearing regions may cause pain and reduce mobility. Medicalintervention such as medications, therapy, or surgery can be required torestore proper function to the damaged area.

Various cartilage defects are often repaired using arthroscopicprocedures to deliver a graft material or a therapeutic material or toperform microfracture. In arthroscopic procedures where therapeuticagents or graft materials are delivered, a dry and isolated sitemaximizes the delivery of a therapeutic agent or graft material to theappropriate location and prevents blood or other ambient fluids fromdiluting or dislodging the graft material or the therapeutic agent. Theisolated implant site also facilitates targeted therapy to the defect.

Accordingly, there is a need for devices and methods of isolatingdefects to provide a dry and separated area at which a localized therapycan be delivered.

SUMMARY

The present teachings provide methods of repairing cartilage defects.The cartilage defect is identified and shaped to prepare the cartilagedefect for a localized therapy. The cartilage defect is isolated with anisolation device. The localized therapy is then delivered to thecartilage defect through the isolation device.

The present teachings also provide methods of repairing cartilagedefects. The cartilage defect is shaped to expose the underlying bone.The underlying bone is then microfractured to induce bleeding. Anisolation device having a barrier device is introduced into the defectand the barrier device is deployed over the defect to isolate a regionof the microfractured bone from an ambient fluid. A positive pressure isapplied from the isolation device to aspirate and dry the isolatedregion. A localized therapy is delivered to the dry isolated region withthe isolation device.

The present teachings also provide methods of repairing cartilagedefects. The cartilage defect is shaped to expose the underlying bone.The underlying bone is isolated from an ambient fluid with an isolationdevice. A negative pressure from the isolation device is applied to drawa blood material from the underlying bone into the cartilage defect. Atherapeutic agent is delivered to the isolated region of the cartilagedefect with the isolation device.

In other embodiments, the present teachings provide methods of repairingcartilage defects. The cartilage defect is shaped to expose anunderlying bone and the bone is isolated using the isolation device. AUV curable composition is delivered to the isolated region with theisolation device. The UV curable composition is cured while theisolation device is isolating the region.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 depicts an isolation device according to the present teachings;

FIG. 2 depicts an isolation device having a mixing chamber according tothe present teachings;

FIGS. 3A, 3B, 3C, and 3D depict various barrier devices according to thepresent teachings;

FIGS. 4A and 4B depict surgical methods according to the presentteachings; and

FIGS. 5A through 5E depict surgical methods according to the presentteachings.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

Referring to FIGS. 1-5E, the present teachings provide various methodsof repairing a cartilage defect 10. Exemplary cartilage defects includethose caused by trauma, excessive use (such as sports injuries, forexample) or diseases, including, but not limited to, osteoarthritis andosteochondrosis dissecans. The defect can be in the form of a focalcartilage defect or a cartilage abrasion, as non-limiting examples.Exemplary implant sites 12 include, but are not limited to, a patella, afemoral condyle, a femoral head, an acetabulum, or any otherarticulating joint surfaces.

Referring to FIGS. 1-3D, the isolation device 14 comprises a syringe 16having a barrier device 18 attached thereto. The syringe 16 comprises abarrel 20 having a proximal end 22, an outlet end 24, a plunger 26, anda plunger seal 28. Collectively, the barrel 20 and the plunger seal 28define an adjustable chamber 30. The chamber 30 can accommodate vacuumpressure and positive pressure. Actuation of the plunger 26 on thesyringe 16 can produce a positive pressure or aspiration or a negativepressure or suction. It is understood that a plurality of chambers 30 orcompartmentalized chambers can be used in conjunction with the isolationdevice 14.

The syringe 16 can be of any suitable size and in various embodimentshas a barrel size or volume of less than about 5 cc. As shown in FIGS.3C and 3D, the syringe 16 can be made of rigid materials adapted to fitwithin the cannula 32 for arthroscopic procedures or can be made ofnon-rigid or semi-rigid materials which flex within the cannula 32. Aflexible syringe 16 is useful to reach a cartilage defect 10 or regionsof the defect where the straight path provided by the cannula 32 isinsufficient. The syringe 16 includes a fitting 34 at the outlet end 24for attachment of a barrier device 18. The barrier device 18 can beremovably connected to the syringe 16 using any suitable technique,including a leur fitting, screw-on, press fit, or snap-on, asnon-limiting examples.

Referring to FIGS. 1 through 3B, the barrier device 18 is shaped forplacement about the cartilage defect 10 to separate the cartilage defect10 from surrounding tissues and/or to bar passage of fluids to thecartilage defect 10. The barrier device 18 comprises an inner surface 19and an outer surface 21. The inner surface 19 is in contact with thecartilage defect 10 while the outer surface 21 serves as the “barrier”against the ambient environment. As shown in FIGS. 1, 3A, and 3B, thebarrier device 18 can be spherical or conical in shape and canoptionally be tapered. The barrier device 18 can be rigid, semi-rigid,or flexible. The barrier device 18 can be made of any biocompatiblematerial, including, but not limited to, rubber, plastic, silicone,glass, metal, or combinations thereof. In embodiments where a flexiblematerial is used, the barrier device 18 flexes to provide the removablyfixed contact with the cartilage defect 10. Where a rigid material, suchas titanium or glass, is used, a gasket can be provided at the base ofthe inner surface 19 to facilitate suction and/or the removably fixedcontact with the cartilage defect 10. The barrier device 18 is designedto accommodate 3-dimensional, planar, arcuate, and jagged surfacesaround the cartilage defect 10. In various embodiments, the barrierdevice 18 is in the form of a suction cup. The inner surface 19 isideally shaped to match the contour of the surface of the cartilagedefect 10.

The size of the barrier device 18 can vary based on the size of thecartilage defect 10. As shown in FIGS. 3C and 3D, the barrier device 18can be a deployable suction cup, for example, and can be housed within aregion of the isolation device 14, for example, the barrel 20 of thesyringe 16. As shown in FIG. 3C, the barrier device 18 is compressed inthe barrel 20 and expands to full size when deployed out of the barrel20 as shown in FIG. 3D. The deployable barrier device 18 is attached tothe syringe 16 such that, although the barrier device 18 can be deployedfrom within the syringe 16, the system remains fluid impermeable tomaintain the integrity and contents of the syringe 16 until the operatorexpels the contents of the chamber 30.

As best shown in FIGS. 1 and 2, the barrier device 18 can be directly orindirectly attached to the syringe 16. Where a direct attachment isused, as mentioned above herein, the barrier device 18 is pressed onto,snapped onto, or screwed onto the outlet end 24 of the barrel 30 usingan attachment feature or fitting 34. The attachment feature 34 allowsfor interchangeable barrier devices 18 to be used with the isolationdevice 14 to accommodate a variety of cartilage defect 10 sizes.

In embodiments where there is an indirect attachment, the barrier device18 is attached over a tube 36 or hose as shown in FIG. 2. The tube 36can be used to provide an enhanced flexibility to the isolation device14. The tube 36 will allow the isolation device 14 to flex and therebyprovide surgical freedom, especially in arthroscopic procedures where aseries of straight cannulas are used to access the surgical site. Thetube 36 can also house a mixing shaft 38. The mixing shaft 38 is usefulin embodiments where two separate components are delivered via theisolation device 14 and need to be mixed immediately prior to deliveryto the cartilage defect 10. As shown in FIG. 2, the mixing shaft 38includes an internal helix to facilitate mixing of the components. Adiaphragm or other structure can also be used in the mixing shaft 38 tofacilitate mixing of the components.

Referring to FIGS. 4A-5E, in various embodiments, the present teachingsprovide methods of repairing cartilage defects, such as focal cartilagedefects, tears, abrasions, and the like. The cartilage defect 10 isidentified and shaped to prepare the cartilage defect 10 for a localizedtherapy. The cartilage defect 10 is then isolated with an isolationdevice 14 to deliver the localized therapy to the cartilage defect 10.The localized therapy is delivered by use of the isolation device 14.

First, a surgical site is prepared either by an open surgical techniqueor arthroscopic surgical technique. Next, the cartilage defect 10 siteis shaped or prepared by removing an area of damaged cartilage to createa defined region such as the plurality of walls 40 a, 40 b, 40 c, 40 dabout the cartilage defect 10, as shown in FIG. 4B. The removal of thedamaged cartilage can include resecting or contouring the cartilage toprovide a region of healthy cartilage and/or underlying bone upon whichto deliver or perform the localized therapy. The defined walls 40 a-40 dand the removal of the damaged cartilage provide a placement area 42 forthe barrier device 18 on the isolation device 14.

As shown in FIGS. 5A-5E, the defined region can be shaped as a circle,oval, or other rounded shape. This allows a round barrier device 18 tomimic the shape of the defined region, as shown in FIG. 5E. It isunderstood that the area around the oval defined region and the removalof the damaged cartilage provide the placement area 42 for the barrierdevice or the isolation device 14.

Providing the healthy surrounding cartilage by shaping or contouring thedefect site, maximizes the effectiveness of the localized therapy andfacilitates integration of new healthy cartilage into the cartilagedefect 10. The damaged cartilage can be trimmed and sized such that thebarrier device 18 fits about and contains the entire cartilage defect10. In various embodiments, the damaged cartilage can be trimmed andsized such that only a region of the cartilage defect 10 is contained bythe barrier device 18.

In addition to providing the placement area, microfracture can beperformed on the cartilage defect 10 to further prepare the cartilagedefect. In microfracture, a small incision is made on the effectedcartilage and a portion of the calcified cartilage 48 is removed fromthe defect site. An awl is then used to create small holes or“microfractures” 52 in the bone under the cartilage defect, as shown inFIGS. 5A-5C, to induce bleeding from the underlying bone into thecartilage defect 10. The blood from the underlying bone 50 containswhole blood and various blood components, including bone marrow and theaccompanying stem cells. The induced bleeding forms a blood clot thatreleases cartilage building cells. It is beneficial to sufficientlyshape the surrounding cartilage such that the microfracture bloodcontaining the chondrocytes can integrate into healthy tissue.Microfracture is particularly useful for cartilage injuries, arthritis,lesions, chondral lesions, and traumatic injuries.

After the cartilage defect site 10 is shaped, the barrier device 18 isplaced over the cartilage defect 10 to isolate the cartilage defect 10from an ambient fluid or from a surrounding tissue (both genericallydepicted as element 44). Ambient fluids include blood, for example, orextracorporeal fluids used to wash the defect site. The surroundingtissue can include various soft tissues, such as muscle, connectivetissues, fat, and the surrounding tissue can also include boney tissue.By isolating the cartilage defect 10, the surrounding tissue is pushedaway from and contained outside of the cartilage defect 10. This isparticularly useful for focal cartilage defects or with microfracturesas the isolation prevents ambient tissue from lying over or in thecartilage defect, thereby blocking the delivery of the localizedtherapy.

The barrier device 18 can be positioned to encase or completely coverthe cartilage defect 10. In various embodiments, the barrier device 18rests on the placement area 42 of surrounding healthy cartilage. Uponpressing the barrier device 18 to the base, the air pressure inside ofthe barrier device 18 is drastically reduced. The relatively higheratmospheric pressure forces the barrier device 18 to stick, suctiononto, or otherwise become removably fixed onto the surface of thehealthy surrounding cartilage.

When the barrier device 18 is in place, the localized therapy is thenadministered. The localized therapy can include delivery of atherapeutic agent 46 or graft material, withdrawing blood from theunderlying bone, or aspirating the cartilage defect 10. It is understoodthat any combination of localized therapies can be used to repair thecartilage defect 10.

In embodiments where the localized therapy includes delivery of atherapeutic agent or graft material, the materials are included at asafe and effective amount that is sufficient to have the desired effectin the human or lower animal subject, without undue adverse side effects(such as toxicity, irritation, or allergic response), commensurate witha reasonable benefit/risk ratio when used in the manner of theseteachings. The specific safe and effective amount of the therapeuticagent 46 will vary with such factors as the particular condition beingtreated, the physical condition of the patient, the nature of concurrenttherapy (if any), the specific therapeutic agent 46 used, the specificroute of administration and dosage form, the carrier employed, and thedesired dosage regimen.

Therapeutic agents 46 useful in the practice of the present teachingsinclude organic molecules, proteins, peptides, antibiotics, analgesics,polysaccharides, glycoproteins, lipoproteins, carbohydrates andpolysaccharides, and synthetic and biologically engineered analogsthereof, growth factors, vitamins, minerals, living cells such aschondrocytes, bone marrow cells, undifferentiated and differentiatedstem cells, cartilage cells, natural extracts, and combinations thereof.The graft materials can include resorbable polymers such aslactocarbonate; polyurethane urea; polymers and copolymers oftrimethylene carbonate, lactic acid, and/or glycolic acid; andcombinations thereof, or natural cartilage. Other suitable therapeuticagents 46 include blood products such as platelet rich plasma,concentrated plasma, fibrin, thrombin, fibrinogen, whole blood, etc. Thetherapeutic agent 46 or graft materials can be in the form of a liquid,a paste, or a gel material.

In various embodiments, the therapeutic agent 46 comprises separatedcomponents which are combined in the mixing shaft 38 of the isolationdevice 14 immediately prior to delivery to the cartilage defect 10. Anexample is a mixture of thrombin and plasma. In such embodiments, theseparated thrombin and plasma combine in the mixing shaft 38 and theappropriate mixing is achieved through the length of mixing shaft 38 asshown in FIG. 2. The mixing can also be facilitated with the diaphragmsor helices as mentioned above herein.

The therapeutic agent 46 can be delivered from within the isolationdevice 14 with sufficient pressure to cause the therapeutic agent totranscend a calcified cartilage layer 48 at the cartilage defect 10 andinfiltrate the underlying bone 50. Infiltrating the underlying bone 50and tissue with the therapeutic agent 46, such as a growth factor, isadvantageous as compared to placement of the therapeutic agent 46 onlyon the surface of the defect because infiltrating the underlying bone 50and tissue expedites healing at the focal cartilage defect 10 andreduces the chances of unintentional dislodging of the therapeutic agentor the graft material from the defect. The therapeutic agent 46 can alsobe delivered to rest within the cartilage defect and not transcend thecalcified cartilage layer 48 and the underlying bone 50. The therapeuticagent 46 fills the shaped cartilage defect 10 as shown in FIG. 5D.

In other various embodiments, the localized therapy includes drawingblood material from the underlying bone 50 into the cartilage defect 10using suction. The cartilage defect 10 is shaped to expose theunderlying bone 50 and isolated from ambient fluids and materials asdescribed above herein. A negative pressure is applied from theisolation device 14 to draw a blood material (including bone marrow andstem cells) from the underlying bone 50 into the cartilage defect 10.The pressure applied is an amount sufficient to draw blood material fromdeep within the cancellous bone. Those skilled in the art appreciatethat the combination of syringe size, cartilage defect size, and thedesired amount of material removed by the negative pressure areconsidered in selecting the amount of negative pressure to apply.

The isolation device 14 can also be used to apply a positive pressure toaspirate and dry the region. Aspirating the region can be used toprepare the cartilage defect 10 for drawing blood from the underlyingbone 50. Aspirating the region can also be used to prepare a drycartilage defect or to remove debris from the cartilage defect 10 priorto application of a therapeutic agent or a graft material.

In still other embodiments, the localized therapy can include a UVcurable localized therapy. The cartilage defect 10 is shaped to exposethe underlying bone 50 and the region is isolated from ambient fluidsand materials as detailed above herein. A UV curable composition is thendelivered to the isolated region with the isolation device 14. The UVcurable composition 46 is cured by exposing the therapeutic agent 46 tothe UV light while the barrier device 18 is isolating the region.

After the isolation device 14 is placed over the cartilage defect 10 toisolate the defect from the ambient fluids and tissue, a UV light sourceis placed at the cartilage defect 10 site through the isolation device14, a nearby cannula, or through a side port or second arthroscopicopening. For example, the UV light can be delivered to the surface of abarrier device 18 that is sufficiently transparent or contains regionsof the transparency to facilitate passage of the UV light therethrough.Where the UV light is administered through the syringe 16 of theisolation device 14, a fiber optic cable can be employed to fit in thesyringe 16. The duration and intensity of the UV light application isselected based on the size of the cartilage defect and the UV curablemonomers employed.

The isolation device 14 is advantageously used with UV curable localizedtherapy because the UV curable components can be sensitive to aqueousenvironments such as in vivo conditions and/or the curing time may beincreased in aqueous environments. The UV curable components useful inthe present teachings include those curable monomers which arebiocompatible and which form biocompatible polymers upon curing. It isalso advantageous to minimize the heat generation from thepolymerization reactions and application of the UV light during curing.

It is understood that the therapies and surgical techniques detailedabove herein can be applied to an implant at the cartilage defect 10.For example, the isolation device 14 can be used to apply therapies toan osteochondral plug, over a bone screw, over a staple, or otherimplant. Example materials to which the isolation device 14 can delivera therapy include, but are not limited to, calcium phosphates, polymersand co-polymers of lactic acid and glycolic acid, calcium sulfate,collagen, or an allograft material.

The description of the present teachings is merely exemplary in natureand, thus, variations that do not depart from the gist of the presentteachings are intended to be within the scope of the present teachings.Such variations are not to be regarded as a departure from the spiritand scope of the present teachings.

What is claimed is:
 1. A method of repairing a cartilage defectcomprising: a. identifying the cartilage defect; b. contouring thecartilage defect to prepare the cartilage defect for a localizedtherapy; c. isolating the cartilage defect with a barrier device of anisolation device by deploying the barrier device out from within asyringe of the isolation device, the barrier device moves from acollapsed position to an expanded position as the barrier device isdeployed; and d. providing the localized therapy to the cartilage defectwith the isolation device.
 2. The method of claim 1, wherein contouringthe cartilage defect further comprises removing the damaged cartilage tocreate a defined uniform region at the cartilage defect.
 3. The methodof claim 1, wherein contouring the cartilage defect comprises removingthe damaged tissue to define within the cartilage a placement area for abarrier device region of the isolation device.
 4. The method of claim 3,wherein the barrier device is sized to surround and contain thecartilage defect.
 5. The method of claim 1, wherein isolating thecartilage defect comprises isolating the cartilage defect from at leastone of an ambient fluid and a surrounding tissue.
 6. The method of claim4, wherein the barrier device comprises a dome-shaped suction cupconfigured to mimic the shape of the contoured cartilage defect andextend beyond a perimeter of the contoured defect.
 7. The method ofclaim 1, wherein the localized therapy is selected from the groupconsisting of: delivery of a therapeutic agent using the isolationdevice, withdrawal of blood from an underlying bone using the isolationdevice, applying a negative pressure to the cartilage defect using theisolation device, applying a positive pressure using the isolationdevice, aspirating the cartilage defect using the isolation device,delivery of a UV curable composition using the isolation device, andcombinations thereof.
 8. The method of claim 7, wherein the localizedtherapy is delivery of a therapeutic agent and the therapeutic agentcomprises separated components further wherein the separated componentsare combined in a mixing shaft between a barrel and a barrier device ofthe isolation device immediately prior to delivery to the cartilagedefect.
 9. The method of claim 1, wherein providing localized therapycomprises drawing blood from within a bone underlying the cartilagedefect using the isolation device.
 10. A method of repairing a cartilagedefect comprising: a. resecting the cartilage defect to expose anunderlying bone; b. microfracturing the underlying bone to inducebleeding; c. introducing an isolation device having a barrier deviceonto the cartilage defect; d. deploying the barrier device and arrangingthe barrier device over the cartilage defect to isolate a region of themicrofractured bone from an ambient fluid, the isolation devicecomprises a syringe configured to house the barrier device in acollapsed position, and deploying the barrier device from within abarrel of the syringe, the barrier device moves from the collapsedposition to an expanded position as the barrier device is deployed; e.applying a positive pressure from the isolation device to aspirate anddry the isolated region; and f. providing a localized therapy with theisolation device to the isolated region.
 11. The method of claim 10,wherein resecting the cartilage defect comprises creating a defineduniform region at the cartilage defect to provide a placement area forthe barrier device.
 12. The method of claim 11, wherein the barrierdevice includes a dome-shaped suction cup sized to surround and containthe cartilage defect.
 13. The method of claim 12, further comprisingdefining a portal to the cartilage defect, inserting the syringe throughthe portal, and flexing the syringe to place the syringe at thecartilage defect.
 14. The method of claim 10, wherein the localizedtherapy comprises delivery of a therapeutic agent with the isolationdevice.
 15. The method of claim 14, wherein the therapeutic agentcomprises separated components combined in a mixing shaft on theisolation device between the barrel and the barrier device of theisolation device immediately prior to delivery to the cartilage defect.16. The method of claim 14, further comprising delivering thetherapeutic agent using the isolation device at a pressure sufficient tocause the therapeutic agent to transcend a calcified cartilage layer atthe cartilage defect and infiltrate the underlying bone.
 17. The methodof claim 10, wherein providing the localized therapy with the isolationdevice comprises drawing blood from within a bone underlying thecartilage defect by applying a negative pressure from the isolationdevice.
 18. A method of repairing a cartilage defect comprising: a.contouring the cartilage defect to expose an underlying bone; b.isolating a region of the underlying bone from an ambient fluid at thecartilage defect with an isolation device by deploying a barrier deviceout from within a syringe of the isolation device to move the barrierdevice from a collapsed position to an expanded position as the barrierdevice is deployed; c. providing a localized therapy by applying anegative pressure from the isolation device to draw a blood materialfrom the underlying bone into the cartilage defect; and d. providing alocalized therapy by delivering a therapeutic agent to the isolatedregion of the cartilage defect with the isolation device.
 19. The methodof claim 18, wherein the negative pressure is applied in an amountsufficient to draw a blood material from within cancellous bone, thepressure is applied with a suction cup of the barrier device.
 20. Themethod of claim 18, wherein delivery of the therapeutic agent with theisolation device is at a pressure sufficient to cause the therapeuticagent to transcend a calcified cartilage layer at the cartilage defectand infiltrate the underlying bone.
 21. A method of repairing a focalcartilage defect comprising: a. contouring the cartilage defect toexpose an underlying bone; b. isolating a region of the bone from anambient fluid at the cartilage defect with an isolation device bydeploying a barrier device out from within a syringe of the isolationdevice to move the barrier device from a collapsed position to anexpanded position as the barrier device is deployed; c. providing alocalized therapy by delivering a UV curable therapeutic agent to theisolated region with the isolation device; and d. curing the UV curabletherapeutic agent while isolating the region with the isolation device.22. The method of claim 21, wherein contouring the cartilage defectcomprises removing the damaged tissue to provide a uniform placement forthe barrier device.
 23. The method of claim 21, wherein the barrierdevice is dome-shaped and sized to surround and contain the cartilagedefect.
 24. The method of claim 21, further comprising exposing theisolated, UV curable composition to a UV light.
 25. The method of claim24, wherein the UV light is placed at the cartilage defect site througha cannula.
 26. The method of claim 21, wherein isolating a region of thebone further comprises defining a portal to the cartilage defect anddelivering the syringe through a cannula to the cartilage defect. 27.The method of claim 26, wherein the UV light is delivered through acannula.
 28. The method of claim 24, wherein the UV light is deliveredwith a fiber optic system.
 29. The method of claim 24, furthercomprising delivering the UV light through a side port or a secondarthroscopic opening.
 30. The method of claim 24, further comprisingdelivering the UV light to the surface of the barrier device.